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Low Hours On Old Engine


araborn12
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Hey everyone! New guy here and I have been casually browsing for Mooney's over the last few months. I have narrowed my search down to a M20J. It fits my mission perfectly.

I went and looked at an M20J today and, on paper, it looks great. Low AF time, 2189, and a TSMOH of 98 hours on the IO-360. Sounds great. Until I get the log books and notice that the engine and props were overhauled in 2000. I dig through the log books and they look good. The compressions on the last annual were 76, 74, 76, 72. That was 8/14/19 and it appears that the engine has only been run up for a total of 1.3 hours since then. 

Am I wasting my time? No oil analysis have been done. It was suggested by the sellers broker that I could have the cylinders borescoped, but I don't feel like it makes any sense for anyone other than the owner to sink some money into the airplane. With a TBO of 2000 and 12 years on the engine, tell me I should run. And if I shouldn't, why? 

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25 minutes ago, araborn12 said:

Hey everyone! New guy here and I have been casually browsing for Mooney's over the last few months. I have narrowed my search down to a M20J. It fits my mission perfectly.

I went and looked at an M20J today and, on paper, it looks great. Low AF time, 2189, and a TSMOH of 98 hours on the IO-360. Sounds great. Until I get the log books and notice that the engine and props were overhauled in 2000. I dig through the log books and they look good. The compressions on the last annual were 76, 74, 76, 72. That was 8/14/19 and it appears that the engine has only been run up for a total of 1.3 hours since then. 

Am I wasting my time? No oil analysis have been done. It was suggested by the sellers broker that I could have the cylinders borescoped, but I don't feel like it makes any sense for anyone other than the owner to sink some money into the airplane. With a TBO of 2000 and 12 years on the engine, tell me I should run. And if I shouldn't, why? 

A lot depends on where the plane has been sitting.  Dry or wet and salty climate?

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42 minutes ago, araborn12 said:

Hey everyone! New guy here and I have been casually browsing for Mooney's over the last few months. I have narrowed my search down to a M20J. It fits my mission perfectly.

I went and looked at an M20J today and, on paper, it looks great. Low AF time, 2189, and a TSMOH of 98 hours on the IO-360. Sounds great. Until I get the log books and notice that the engine and props were overhauled in 2000. I dig through the log books and they look good. The compressions on the last annual were 76, 74, 76, 72. That was 8/14/19 and it appears that the engine has only been run up for a total of 1.3 hours since then. 

Am I wasting my time? No oil analysis have been done. It was suggested by the sellers broker that I could have the cylinders borescoped, but I don't feel like it makes any sense for anyone other than the owner to sink some money into the airplane. With a TBO of 2000 and 12 years on the engine, tell me I should run. And if I shouldn't, why? 

When were most of the 98 hours flown? Last year after reviving the plane from cold storage and getting back in annual, or many years ago?  The latter situation might make you run. The former might make you still demand pricing as a runout engine - it could still easily bite you in another 50-100hrs. Borescoping is worth doing but lack of concerning findings will still give you no confidence in the longevity of the bottom end of engine - the real wallet buster. Favorable compressions also provide minimal reassurance. Oil analysis is nearly worthless in this situation (and most others). 

There will also be lots of other issues to shake out from a plane that sat so long.  Read the old threads here on this situation carefully!

 

 

 

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32 minutes ago, Davidv said:

A lot depends on where the plane has been sitting.  Dry or wet and salty climate?

Hangared in an air conditioned hangar for the last 24 years. The 98 hours appears to be spread throughout the 20 years. Apparently the man's wife got sick and he just didn't have time to fly. The man is quite wealthy and the plane is meticulously cared for. I just wouldn't want to sink close to $100k on an airplane with a 20 year old engine that hasn't flown. I don't get the warm and fuzzies, and I wanted to see what others thought.

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If it hasn't been flying, has the engine been pickled? If not, the big concern would be internal corrosion. The cylinders could be pitted but the biggest risk is the camshaft which you cannot inspect without some disassembly. As you noted, the engine is beyond the Lycoming 12 year TBO.

I would also be very concerned about the airframe and avionics. Mechanical and electrical components do not like to sit. Electrolytic capacitors in radios go bad. Bearings deteriorate from moisture, etc. I volunteer at a local museum and a lot of the airplanes fly less than 10 hours per year. They are all hangared. We usually find stuff that needs fixing at every annual. The mechanic says he'll never be out of work since they seem to break just sitting there.

If it were me, I'd look for another airplane. But it this one is really the one you want, I would get a very thorough prepurchase inspection including oil analysis and borescoping the cylinders by someone that knows Mooneys well and knows what to look for,  and I would nit pick every little discrepancy (realizing that you won't find them all) and negotiate a deep discount. I would also go into it with a healthy cash reserve tucked away in case it needs an engine replacement and other expensive work.

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9 minutes ago, araborn12 said:

Hangared in an air conditioned hangar for the last 24 years. The 98 hours appears to be spread throughout the 20 years. Apparently the man's wife got sick and he just didn't have time to fly. The man is quite wealthy and the plane is meticulously cared for. I just wouldn't want to sink close to $100k on an airplane with a 20 year old engine that hasn't flown. I don't get the warm and fuzzies, and I wanted to see what others thought.

Ok, as others have mentioned there is a possibility everything is fine with the engine but just know you’ll most likely find things in the first year of ownership and flying that will red to be replaced such as seals and other items that benefit from regular use...

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My first Mooney was low time and because it Sat so much, the cylinders had pitting which I ended up having to do a top end overhaul during the first 100 hrs of flying. A pre-buy should include a borescope. Have the A&P check out known areas.

Planes don't do well sitting so expect possible leaking tanks, seals, etc. and be pleasantly surprised if it's not that bad.

Sent from my Pixel 3a using Tapatalk

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Just look very closely at everything for corrosion, dried seals and gaskets, condition of tires, etc.   If it's been run a few times a year it may be fine, but still worth  looking very closely.

Could be a good find, and you can use the fact that it's been barely used during price negotiations, as that is not a favorable point about the airplane.

 

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A lot depends on where the plane has been sitting.  Dry or wet and salty climate?

I believe this is an urban myth. IMO engine corrosion issues are a result of dirty oil, not moisture or salt in the air. Below is my camshaft that came from my old engine, cleaned of any oil it’s been sitting on the floor of my hangar in SE Florida, only a few miles from the Atlantic Ocean, for more 2 years. Conventional wisdom says it should be a pile of rust by now. It looks the same as I got it.

d125dc23771a06dfacc0fbd611349cf8.jpg
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A big part of this decision has to be based on your own situation and risk aversion/tolerance.  If you're in a financial and mindset situation where you could handle the worst possible outcome, then that allows you more flexibility.  If not, though, then you might want to look for something else...knowing that there are always going to be unknowns and surprises even in the best looking plane.  Personally, I think you go with your gut.  It sounds like this plane has much that interests you and the owner's not left it out in the sun to rot away.  As many will tell you, part of the pre-purchase evaluation is on the owner.  In my case, we bought our E sight unseen from a true gentleman who loved his Mooney...and we couldn't be happier.

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I was looking at a PA18-150 sitting on the Pacific Northwest coast, 36 hours in 5 years on a 600 hour engine.. Do you think I was concerned about engine corrosion? You bet! With a Lycoming you really can't get a good look at the cam and lifters without a lot of disassembly. My solution was I purchased the airplane with a holdout in escrow. the deal with the seller was, I would purchase the airplane, I would fly it to the East Coast, if there was no metal, he would claim the 10K held in escrow. If it was making metal, I get the 10K. It made about a teaspoon of metal, changed the oil and it made some more. So I took the 10K. So a deal is doable, just cover yourself.

If you horoscope the cylinders and see corrosion, you can stick fork in it. It needs an engine.  If not, still a question mark but not a deal killer. Look at it this way. If it is a great airframe, but needs an engine, you price it accordingly, buy it, put in a new engine and you have a damn fine airplane with a known quantity on the engine. IOW, you got something that you may be able to make work for you .Don't walk away, see if it can work out.

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Welcome aboard araborn.

Planes that sit are at more risk than planes that fly often...

metals can corrode... seals can ‘dry’ out... 

cams and cam followers are the most susceptible to being damaged...

 

So...

1) You decide you can handle the risk...

2) You read all the logs, take detailed notes... you decide to go forwards...

3) You get a pre-purchase inspection...

4) PPI comes back good...

5) You fly about 100 hours the first year...

6) At annual, you find a filter full of metal bits from the cam...

7) Do get the engine OH’d or.... are you out of dough, and done flying?

My first Mooney went this way... if I needed an OH, I was done... :)

I got lucky... only need one new cylinder the first year... stuck a valve during Transition Training...

Best regards,

-a-

 

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My first Mooney was a low time E Model.  It had 560 hrs on the engine spread out over 12 years.  I had to put new cylinders on a few years into it, but the engine ran to TBO without issue.

My next Mooney was an even lower time plane, near new, it sat in a hangar for 10+ years.  It’s an Ovation 3GX.  I’ve put about 200 hrs on it since buying it 25 months ago.  

Low time is low time; there’s a trade off on potential engine issues, but you can’t argue with low time.  Buy the plane.  If you’re concerned about the engine, take $10K off the price and buy the plane.

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I think what Tom was saying....

 
If you take The cam out of the engine for inspection.... you will see if any of the lobes have been shortened...
 
In this edited pic... you can sing the song... which one of these lobes is not like the others...  
 
The red one doesn’t look much like a lobe... anymore.
 
PP guessing about what’s in the pic... not a mechanic...
:)
 
Great pic Tom!
 
Best regards,
-a-

352BC3AC-DF32-4301-9E69-ADF7E5AFEEAF.jpeg

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I bought a low time engine IO 540 and Bravo  airframe.  Both had approximately 600 hours TT.  The plane was about 20 years old. The previous owner lost his medical and could no longer fly. The plane had been flown monthly by a friend. It had been kept in a hanger with air conditioning and a humidifier.  The owner was very wealthy and always gave the plane the best of care.  I liked the airframe and panel but was concerned the  engine might fail or be expensive to maintain  I had the engine bore scoped, an oil analysis was done and the cylinder compression was taken.

All the tests were competed. The engine appeared fine. I had an extensive annual on the plane and bought it. I have put more than 150 hours on the engine. It has performed well and been a very good investment for me. 

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  • 2 weeks later...

This is a little tangential to his thread. IO360 and O360 Lycoming engines lubricate the cam with oil that flys off of the crankshaft. My research and reading is that 1000 rpm are required to ensure sufficient lubrication for the cam lobes. There is probably no way to know how the engine has been run, but it is something to consider going forward.

My former Mooney (1965 M20C) sat in a hanger unflown for three years before I sold it. There were 1500 hours on a factory reman engine when I sold it in 2014. I am in touch with a the current owner; it went to Florida and now lives n Allentown NJ. It is flown regularly and the engine is doing fine.

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